= GIET-VM / Miscelaneous kernel functions =

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The [source:soft/giet_vm/giet_common/utils.c utils.c] and [source:soft/giet_vm/giet_common/utils.h util.h] files define various kernel functions that are used both by the boot-loader and by the kernel. 

They are prefixed by "_" to remind that they can only be executed by a processor in kernel mode.


 === void _exit() ===
Processor suicide with a dated message on TTY0 in case of kernel panic.

 === void _random_wait( unsigned int value ) === 
This function implements a pseudo-random delay.
The ''value'' argument define the max number of bits for the delay.
The average delay value is approximately : (2**value) * 2 / 3

 === void _break( char* string ) ===
This blocking function implements an interactive break for kernel debug.

 === unsigned int _strncmp( const char* s1, const char* s2, unsigned int n ) ===
Compare two strings ''s1'' and ''s2'', no more than n characters.

 === char* _strcpy( char* dest, char* source ) ===
Copy source string to dest string.

 === void _dcache_buf_invalidate( void* buffer, unsigned int size ) ===
Invalidate all data cache lines corresponding to a memory buffer identified by a virtual base address and a size.

 === unsigned int _heap_info( unsigned int* vaddr, unsigned int* size, unsigned int x, unsigned int y ) ===
This function returns in the ''vaddr'' and '' size'' arguments the information associated to a heap.
If (x < X_SIZE) and (y < Y_SIZE), it return the heap associated to any task running in cluster(x,y). 
Else, it return the heap associated to the calling task.
It uses the mapping_info structure to retrieve information, and return 0 if success. Return non zero if not found.